/**
 * $RCSfile$
 * $Revision$
 * $Date$
 *
 * Copyright 2003-2007 Jive Software.
 *
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jivesoftware.smackx.provider;

import org.jivesoftware.smack.packet.PacketExtension;
import org.jivesoftware.smack.provider.PacketExtensionProvider;
import org.jivesoftware.smack.util.StringUtils;
import org.jivesoftware.smackx.packet.XHTMLExtension;
import org.xmlpull.v1.XmlPullParser;

/**
 * The XHTMLExtensionProvider parses XHTML packets.
 * 
 * @author Gaston Dombiak
 */
public class XHTMLExtensionProvider implements PacketExtensionProvider {

	/**
	 * Creates a new XHTMLExtensionProvider. ProviderManager requires that every
	 * PacketExtensionProvider has a public, no-argument constructor
	 */
	public XHTMLExtensionProvider() {
	}

	/**
	 * Parses a XHTMLExtension packet (extension sub-packet).
	 * 
	 * @param parser
	 *            the XML parser, positioned at the starting element of the
	 *            extension.
	 * @return a PacketExtension.
	 * @throws Exception
	 *             if a parsing error occurs.
	 */
	public PacketExtension parseExtension(XmlPullParser parser)
			throws Exception {
		XHTMLExtension xhtmlExtension = new XHTMLExtension();
		boolean done = false;
		StringBuilder buffer = new StringBuilder();
		int startDepth = parser.getDepth();
		int depth = parser.getDepth();
		String lastTag = "";
		while (!done) {
			int eventType = parser.next();
			if (eventType == XmlPullParser.START_TAG) {
				if (parser.getName().equals("body")) {
					buffer = new StringBuilder();
					depth = parser.getDepth();
				}
				lastTag = parser.getText();
				buffer.append(parser.getText());
			} else if (eventType == XmlPullParser.TEXT) {
				if (buffer != null) {
					// We need to return valid XML so any inner text needs to be
					// re-escaped
					buffer.append(StringUtils.escapeForXML(parser.getText()));
				}
			} else if (eventType == XmlPullParser.END_TAG) {
				if (parser.getName().equals("body")
						&& parser.getDepth() <= depth) {
					buffer.append(parser.getText());
					xhtmlExtension.addBody(buffer.toString());
				} else if (parser.getName().equals(
						xhtmlExtension.getElementName())
						&& parser.getDepth() <= startDepth) {
					done = true;
				} else {
					// This is a check for tags that are both a start and end
					// tag like <br/>
					// So that they aren't doubled
					if (lastTag == null || !lastTag.equals(parser.getText())) {
						buffer.append(parser.getText());
					}
				}
			}
		}

		return xhtmlExtension;
	}

}
